TY - BOOK AU - Maha Salah Abdelmoneim AU - Ahmad A. Amer , AU - Shaaban S. Khalil , TI - Inflation in f(R) modified gravity / PY - 2017/// CY - Cairo : PB - Maha Salah Abdelmoneim , KW - f(R) KW - Inflation KW - Modified gravity N1 - Thesis (M.Sc.) - Cairo University - Faculty of Science - Department of Mathematics; Issued also as CD N2 - Despite some of its successful features, the standard big bang cosmology su{uFB00}ers from many problems. The Flatness and Horizon problems are two of its main un- solved problems. In{uFB02}ationary cosmology is an alternative framework to standard cosmology within which the in{uFB02}ation solves some of these problems e{uFB03}ciently. Many scenarios of in{uFB02}ation are invented. The original version of in{uFB02}ation was based on adding a scalar {uFB01}eld to the energy-momentum at the early Universe whose dynamics causes the in{uFB02}ation. Other alternatives depend on modifying the geometrical part of the general theory of relativity. The f(R) modi{uFB01}ed theory of gravity is one of the most straightforward generalizations of such examples. However f(R) serves again as the general relativity minimally coupled with a geometry-inspired scalar degree of freedom. In{uFB02}ation in f(R) theories is one of the active topics of research these days. In{uFB02}ation in the framework of f(R) modi{uFB01}ed gravity is revisited. We study the conditions that f(R) should satisfy in order to lead to a viable in{uFB02}ationary model in the original form and in the Einstein frame. Based on these criteria we propose a new logarithmic model as a potential candidate for f(R) theories aiming to de- scribe in{uFB02}ation consistent with observations from planck satellite (2015). The model predicts scalar spectral index 0.9615